Magneto mechanism



Aug- 12, 1958 R. E. PHELoN 2,847,491

MAGNETO MECHANISM Filed March 2, 1956 INVEN'T'CJR RL.) SSEI-L E. PI-IELON ATTORNEYS United States Patent() MAGNET() MECHANISM Russell E. Phelon, Longmeadow, Mass.

Application March 2, 1956, Serial No. 569,110

9 Claims. (Cl. 12B- 149) The invention relates generally to a magneto of the flywheel type and it relates more particularly to a magneto and engine assembly which includes an improved mounting means for the stato-r of the magneto. A mechanism embodying the present invention is in some respects similar to that set forth in the copending application of Russell E. Phelon, Serial No. 492,158, filed March 4, 1955, and entitled Magneto Mechanism.

The general object of the present invention is to provide a magneto and engine assembly wherein the core of the stator is mounted directly on the engine plate but is so mounted in such a manner that the engine plate requires a minimum of machining, thus reducing the cost for a magneto not requiring extreme accuracy.

In the drawing l have shown in detail a preferredembodiment of the invention, butit will be understood that various changes may be made from the construction shown, and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose. i

Of the drawing:

Fig. 1 is a transverse sectional View of a magneto embodying the invention, the View being taken along the line 1-1 of Fig. 2.

Fig. 2 is a longitudinal sectional view taken along the line 2-2 of Fig. l.

Fig. 3 is a fragmentary sectional view taken along the line 3 3 of Fig. l. n

Fig. 4 is a fragmentary sectional View taken along the line 4-4 of Fig. l.

' Fig. 5 is an enlarged View similar to the front portion of Fig. 3, but showing the partsin an intermediate position of assembly.

Fig. 6 is a View similar to Fig. 5, but showing the core plate in its fully engaged position.

Referring to the drawings, it will be apparent that the magneto shown is of the type wherein the rotor is carried by or is formed as a part of the flywheel and wherein the rotor surrounds, or at least partly surrounds, the stator. Within the scope of the present invention the-rotor and the stator may be widely varied not only Vas to mechanical details but also as to magnetic circuits. Except as to the hereinafter described features of novelty, the rotor and stator structures as shown and described are intended to be merely exemplary.

The stator of the magneto to which the invention more particularly relates is carried or adapted to be carried by an engine frame or plate 10 having an opening in which is located a bearing 12 fora rotatable shaft 14, the shaft extending through said opening and projecting beyond the front face of said plate. The shaft 14 may be an extension of the crankshaft of the engine with which the magneto is to be used, and in any event it is rotated in timed relationship with the engine. The stator comprises a magnetic core 16 which has parallel front` and'rear faces and is preferably laminated. Said'cor'e 16 is conice structed and arranged to provide a plurality of circularly spaced poles having arcuate faces concentric with the axis of the shaft 14 and equi-distant therefrom. As shown, the core 16 has three poles 18, 20 and 22, and

primary and secondary coils 24 and 26 surround thel intermediate pole 20. The primary coil has a relatively small number of turns, as for instance 175, and the secondary coil has a relatively large number of turns, as for instance 10,000. l

The primary coil 24 is suitably grounded at one end,

for instance by being connected by a conductor 28 with` a screw 30. The ungrounded end of the primary coil is connected by means of insulated conductors 32 and 34 With suitable circuit making and breaking mechanism which may be remote from the stator and which is not shown. Preferably a secondary coil 26 also surrounds said intermediate pole 20, said coil being also suitably grounded, for instance by being connected by a conductor 36 with said grounding screw 30. The secondary coil is provided at its ungrounded end with an insulated conductor 38 by means of which it is connectible with the spark plug of the engine. 4

A condenser 40 is connected with the core 16,` being held by a clip 42 attached to the plate byv a screw 44. Said conductors 32 and 34 are shown as being connected with a terminal 46 on the condenser. It will be obvious that the condenser is connected in parallel with the breaker mechanism.

The rotor of the magneto includes a flywheel 48 which is connected with the shaft 14 so as to be rotatable therewith.- The flywheel is shown as having a disc-like outer or front wall carrying an annular flange 50 which surrounds the before-described stator. The inner or internal face of the annular flange 50 is preferably cylindrical at least in part. As shown, the flange 50 has an annular rabbet 52 for receiving an annular flange on theengine plate 10. As shown, the magneto rotor comprises not only said flywheel but also a magnet unit of the type set forth in the Phelon Patent No. 2,538,534, dated January 16, 1951, and entitled Rotor for Flywheel Magneto and Magnet Unit Therefor. i

The magnet unit includes an arcuate connecting member 54 which is formed of magnetic material and which is attached by screws 56, 56 to the inner face of thev flywheel flange 50. Secured to the connecting member 54 are two similar permanent magnets 58 and 60 which are oppositely charged radially. Connected with the magnets 58 and 60 at the inner ends thereof are arcuate p'ole pieces 62 and 64 formed of magnetic material. The inner faces of the pole pieces 62 and ori are concentric with the axis of the shaft 14 and said faces are so positioned that upon rotation of the flywheel they move in close proximity to the outer faces of the core lplate poles 18, 20 and 22.

The flange 50 of the flywheel has a portion 65 which is thicker than the portion to which the connecting member 54 is attached, this thicker portion 65 serving as a counterweight for the magnets 58 and 60 and for the connecting member and pole pieces associated therewith.

During each rotation, the magnets and the pole pieces therefor cooperate with the poles of the stator to establish a magnetic circuit in one direction ,through the, center pole 20 and through the coils thereonv and then to establish a similar circuit in the opposite direction. Thus the direction of the magnetic circuit is suddenly reversed and a maximum value of Voltage is established in the primary coil Z4. The breaker mechanism, not shown, is timed to break the circuit in the primary coil at approximately the instant of maximum voltage there-thus generating a high voltage in the secondary coil 2-6 whichl is connected with the spark plug, not shown,

The engine plate is provided with at least one and preferably two forward integral projections which are engageableA by the core, said projections serving to locate the core and prevent any transverse movement thereof. The projections are preferably of suchsize and shape and location that, upon rearward movement of the core during assembly, portions of said projections are engaged by sharp corners on portions of the core. Continued rearward movement of the core causes said sharp corners to serve as cutting edges which shave the metal of the projections. The described shaving of the metal ofthe projections insures an accurate fit between said projections or bosses and saidv portions of the core.

Preferably the projections initially have inclined lateral faces and said sharp corners or cutting edges on said core 16,*upon rearward movement of said core during assembly, first engage said initial inclined faces of theprojections. l After such engagement, continued rearward movement-of the core causes said cutting edges thereon to shave the metal of thev projections at said inclined faces thereof to insure an accuratel tit as aforesaid.

Preferably and as shown, one of said integral forward projections on said engine plate is a boss or dowel 66 andthe laminated core 16 has an openingtherein for receiving and litting said dowel. Means is provided for preventing any rotative movement of the core 16 about the axis of the dowel 66 and this means may be a second dowel 68 similar to the dowel 66 andsimilarly entered inan opening in the core. The two dowels 66 and 68 arewidely spaced from each other and they project from forwardly located integral pads 70 and 72 having front faces which engage the rear face of the core 16. Said dowels are preferably tapered to provide inclined lateral facesas before mentioned. The holes or openings in theV core for receiving the dowels are respectively designated 74v and 76. SaidV openings are spaced to respectively register with and receive said dowels 66 and 68, the hole 74 being shown in Figs.` l, 3 and 5 and the hole 76 being shown in Fig. 4. The core is held against forward movenient away from the pads by screws 78 and 80j, said screws extending through Unthreaded holes in the core and into threaded holes in the pads. The last said holes in the core are considerably larger than the screws so that said screws do not alfect or interfere with the location of the core by said dowels 66` and 68.

For convenience and as shown in Fig. 4, the hole 76 for the dowel 66 is threaded at its forward end so as to receive the screw 44 for the condenser clip 42.

The formation and functioning of the projections or dowels 66 and 68 will be more clearly understood from Figs. 5 and 6 which show the dowel 66 and associated parts on an enlarged scale. The core 16 is shown in' Fig. 5 as being in a position of partial assembly with the sharp corner at the edge of the hole in engagement with a portion of the dowel 66. When the dowel 66 is tapered to provide an inclined lateral face, it will be evident that the core can be moved rearwardly without resistance to about the position shown in Fig. 5 with the dowel partly entered in the hole. After reaching the position shown in Fig. 5 the core is forced rearwardly into engagement with the pads as shown in Fig. 6. In moving rearwardly from the Fig. 5 position to the Fig. 6 position the sharp corner at the inner end of the hole 74 serves as a cutting edge to shave the metal of the dowel 66 at the larger inner portion thereof. A groove 82 is preferably formed in the face of the pad 70 around the dowel 66 and this groove receives any chips or shavings so that they will not obstruct the movement ofthe core into full engagementwith the dowels and with the pads. Chips in the groove are indicated at 84 in Fig. 6. The core may be forced rearwardly by means of the screws 78 and 80 and these screws serve to hold the core in its' nal position. However, thescrews do not interfere with the centering of the'core by the dowels;

From the foregoing description' it will be` evident that 4. the projections or dowels 66 and 68 serve as the sole means for locating or centering the'core. In accordance with the invention set forth in said application, Serial No. 492,158, the core is located and centered by means of a machined exterior cylindrical surface on a boss which is shown as being the hub of the engine plate. The construction shown in said application wherein the boss is a hub has the advantaget ofi. great accuracy in the concentricity of the pole faces such asthose at 18, 20 and 22 with the shaftaxis, but the present construction avoids` the necessity for an accurately machined exterior surface on the hub and it is entirely satisfactory when a lesser degree-of accuracy is sufficient.

The holes 74 and '76: are accurately spaced and located in the die formed laminations of the core, and the projections or dowels 66 and 68 are reasonably accurately spaced and located by die casting or otherwise. By reason of the described shaving operation, the shaved projections or'dowels closely t the holes. Furthermore, if there is'any small error in the positions of one dowel, this error is only partly transmitted to the core;

an equalization withY resultant reduction in error.

The invention claimed is:

1. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and`having two' integral forward projections extending from the front'face of said plate which projections are unobstructed at' their front ends, a rotatable shaft having a portion extending through said' plate opening' and projecting beyond the front face of said plate, a core formed of laminated magnetic metal and shaped to' provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being formed and shaped to provide two'portions which respectively engage and flt the sides `of said integral projections on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said shaft, said projections and.' said core being so related to each other that said core is longitudinally movable into its fully engaged position on said projections, means engaging said core toprevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one of said poles ofthe core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and includinga magnet and pole pieces movable in close proximity to said pole faces ofthe stator.

2. A magneto and engine assembly comprising in comand projecting beyond the front face of said plate, a coreformed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being provided withtwo portions which respectively engage and fit said integral projections on said engine plate so as to prevent any movement of saidgcore perpendicularly to the` axis of saidshaft, the last said portions ofthe core having cutting edges engageable with the initial lateral portions of the projections sol that the core in moving into full engagement with said projections has sheared metal therefrom, means engaging said coreto prevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one of said poles of the core and cooperatingwith said core to constitute av stator, and a rotor carried by the projecting portion of said' rotatable'shaft and' including a magnet and pole pieces movable in close proximity to said pole faces of the bination, astationary engine plate having an opening.

thereini and: having. two.. integral forward projections .ex-1

The simultaneous shaving of the two dowels servesto effecttending from thefront face of said plate and initially having inclined lateral faces, a rotatable shaftv having a portion extending through said plate opening and projecting beyond the front face of Said plate, a core formed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being provided with two portions which respectively engage and fit said integral projections on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said shaft, the last said portions of the core plate having cutting edges engageable with the initial inclined lateral faces of the projections so that the core in moving into full engagement with said projections has sheared metal therefrom, means engaging said core to prevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

4. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and having two integral dowels projecting forwardly from the front face of said plate, a rotatable shaft having a portion extending through said plate opening and projecting beyond the front face of said plate, a core formed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being provided with two holes which respectively receive and t said integral dowels on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said shaft, means engaging said core to prevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one `of said poles of the core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces -of the stator.

5. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and having two integral pads projecting forwardly from the front face of said plate and having their front faces in the same transverse plane, each of said pads having an integral dowel projecting forwardly from the front face of said pad, a rotatable shaft having a portion extending through said plate opening and projecting beyond the front face of said plate, a core formed of laminated magnetic metal engaging the front faces of said pads and shaped to provide a plurality of poles having faces equally spaced from the 'axis of the shaft, said core being provided with two holes which respectively receive and ilt said integral dowels on said pads so as to prevent any movement of said core perpendicularly 4to the axis of said shaft, means engaging said core to prevent forward movement thereof away from said pads, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

6. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and having an integral dowel projecting forwardly from the front face of said plate and initially tapered forwardly so as to have -a smaller diameter at the front and a larger diameter at the rear, a rotatable shaft having a portion extending through said plate opening and projecting beyond the front face of said plate, a core formed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being provided with a hole which receives and lits said integral dowel on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said dowel, said hole having a diameter 'greater than the initial front diameter of said dowel and smaller than lthe initial rear diameter of said dowel so that the core in moving into engagement with said dowel has sheared metal therefrom, primary and secondary coils surrounding one of said poles of the core and4 cooperating with said core Vto constitute a stator, means engaging said core for preventing rotative movement of said stator about the axis of said dowel, means engaging said core to prevent forward movement of said stator away from said engine plate, and a rotor carried -by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

7. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and having two integral dowels projecting forwardly from the front face of said plate and initially tapered forwardly so as to have smaller diameters. at the front and larger diameters at the rear, a rotatable shaft having a portion extending through said plate opening and projecting beyond the front face of said plate, a core formed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core being provided with two holes which respectively receive and t said integral dowels on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said shaft, said holes having diameters 4greater than the initial front diameters of said dowels and smaller than the initial rear diameters of said dowels so that the core in moving into engagement with said dowels has sheared metal therefrom, means engaging said core to prevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

8. A magneto and engine assembly comprising in combination, a stationary engine plate having an opening therein and having two integral pads projecting forwardly from the front face of said plate and having their front faces in the same transverse plane, each of said pads having an integral dowel projecting forwardly from the front face of said pad which dowel is initially tapered forwardly so as to have a smaller diameter at the front and a larger diameter at the rear and each of said pads also having an annular groove in its front face surrounding the corresponding dowel, a rotatable shaft having a portion extending through said plate opening and projecting beyond the front face of said plate, a core formed of laminated magnetic metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having two holes which respectively receive and fit said integral dowels on said engine plate so as to prevent any movement of said core perpendicularly to the axis of said shaft, said holes having diameters greater than the initial front diameters of said dowels and smaller than the initial rear diameters of said dowels so that the core in moving into engagement with said dowels has sheared metal therefrom which sheared metal has moved into said grooves, means engaging said core to prevent forward movement thereof away from said engine plate, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

9. A magneto and engine subassembly comprising in eQmbination,-, a stationary engine. plate having..i an opening,- therein andI having two integraltdowelsprojecting forwardlyffrom the rontrface'. oisaidfplte and initially tapered forwardlyr sov asl to have, smaller. dia-meters' at thefront and` larger diameters-at the rear, ancore formed `oflaminated magnetiernetal and shaped 4'co providefa plurality of poles having faces equally 4spaced-from the center of said opening, said. core being prorvidedywith two holes having diameters g1-eater., than u the initial frent diameters ofy saidA dowels and, smallerv than. the initial rear diameters of said-dowels and-saidcoreb'eing posi- 1,463,958". Kettering .Aug.' 7,1923

FOREIGN PATENTS 1,47'3 Australia, Api-Qv 17; 1'926 

